Hello,
It could be a CSS conflict, due to lack of specificity.
https://www.smashingmagazine.com/2007/07/css-specificity-things-you-should-know/
When you merge CSS, conflicts may arise.
You can try to read our faqs on how to test and how to use the ignore list to exclude files.
https://wordpress.org/plugins/fast-velocity-minify/faq/
Thank you very much for the answer!
I don’t merge CSS into a single file, I put it out in html. So there are shouldn’t be problems with lack of specificity.
The problem is with js
Did you try following the faqs, where it says, to disable each feature one by one, until you determine the type or error?
If you know that it’s javascript based, then all you need to do is to use the ignore list. It may be a completely unrelated script, not necessarily the one triggering an error. You need to try them all until you find the one causing it.
Also, if you are inlining all css, that can also lead to specificity issues. Code that were in files, have now the same priority as inlined code, when before it was less.